UC IPM: UC Management Guidelines for Seedcorn Maggot on Cotton

UC Pest Management Guidelines

Cotton

Seedcorn Maggot

Scientific Name: Delia platura

(Reviewed 1/08, updated 1/08)

In this Guideline:

Description of the pest
Damage
Management

The adult is a light gray fly about 0.2 inch (5 mm) long. Larvae are white, cylindrical, tapered anteriorly, and are also about 0.2 inch (5 mm) long. Larvae can be found inside damaged seeds or in the soil nearby.

Damage generally occurs in localized areas of the field and appears as areas where seedlings have not emerged. Seedcorn maggots hollow out seeds or eat portions of seedlings. Damage is most common in early plantings when the soil is cool, especially in fields with lots of organic matter. Damage tends to be worse on sandier soils.

If cotton follows corn in a crop rotation, seed corn maggot may become a problem, especially if crop residue is present in soil for the maggot to overwinter on. Once damage occurs it is too late to treat. A slurry seed treatment is the best preventive control if cotton must be planted early in fields with high levels of decaying organic matter. Planting later in spring when the soil isn't excessively moist and soil temperatures are warmer will help to reduce damage by this pest. Also, destroying vegetation from the previous crop at least 1 month before planting should help minimize damage.

Common Name

Amount/100 lb seed**

R.E.I.+

P.H.I.+

(trade name)

(hours)

(days)

When choosing a pesticide, consider information relating to efficacy, selectivity, persistence, impact on honey bees and enviromental impact.

CHLORPYRIFOS

(Lorsban) 30 Flowable

5.5 oz

SELECTIVITY: High

PERSISTENCE: Pest–Moderate; Natural Enemies–Short

MODE OF ACTION GROUP NUMBER¹: 1B

COMMENTS: Slurry treatment with appropriate delinted seed fungicide. Toxic to fish, birds and other wildlife. Keep out of any body of water and off of the soil surface.

**	Mix with sufficient water to create a slurry.
+	Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (P.H.I.) is the number of days from treatment to harvest. In some cases the REI exceeds the PHI. The longer of two intervals is the minimum time that must elapse before harvest.
¹	Rotate chemicals with a different mode-of-action Group number, and do not use products with the same mode-of-action Group number more than twice per season to help prevent the development of resistance. For example, the organophosphates have a Group number of 1B; chemicals with a 1B Group number should be alternated with chemicals that have a Group number other than 1B. Mode of action Group numbers are assigned by IRAC (Insecticide Resistance Action Committee). For additional information, see their Web site at http://www.irac-online.org/.

UC IPM Pest Management Guidelines: Cotton
UC ANR Publication 3444
Insects and Mites
L. D. Godfrey, Entomology, UC Davis
P. B. Goodell, UC IPM Program, Kearney Agricultural Center, Parlier
E. T. Natwick, UC Cooperative Extension, Imperial Co.
D. R. Haviland, UC IPM Program, Kern Co.
Acknowledgment for contributions to the insects and mites section:
E. E. Grafton-Cardwell, Kearney Agricultural Center, Parlier
N. C. Toscano, Entomology, UC Davis

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How to Manage Pests

UC Pest Management Guidelines

Cotton

Seedcorn Maggot

Scientific Name: Delia platura

DESCRIPTION OF THE PEST

DAMAGE

MANAGEMENT

PUBLICATION